Method of assembling a cable routing system

ABSTRACT

A telescoping cable trough section is provided including first and second U-shaped trough sections which are slideably received with each other. One trough section includes slots, and the other includes flanges received in the slots for mating the two trough sections together to form the telescoping cable trough section.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of application Ser. No. 09/578,300,filed May 25, 2000, which application is incorporated herein byreference now U.S. Pat. No. 6,739,795.

FIELD OF THE INVENTION

This application relates to a system for the management and routing ofoptical fiber cables and other telecommunications cables. Particularly,this application relates to a trough member for use with other troughs,couplings, and fittings.

BACKGROUND OF THE INVENTION

In the telecommunications industry, the use of optical fibers for signaltransmissions is accelerating. With the increased utilization of opticalfiber systems, optical fiber cable management requires industryattention.

One area of optical fiber management that is necessary is the routing ofoptical fibers from one piece of equipment to another. For example, in atelecommunications facility, optical fiber cables may be routed betweenfiber distribution equipment and optical line terminating equipment. Inbuildings and other structures which carry such equipment, the cablerouting can take place in concealed ceiling areas or in any other mannerto route cables from one location to another.

When routing optical fibers, it is desirable that a routing system willbe easy to assemble, readily accessible and adaptable to changes inequipment needs. Accordingly, such routing systems include a pluralityof trough members such as troughs and couplings for forming the cablerouting paths. The trough system members are joined together bycouplings. U.S. Pat. No. 5,067,678 to Henneberger et al dated Nov. 26,1991 concerns a cable routing system that includes a plurality oftroughs and fittings. The '678 patent further discloses a coupling(element 250 in FIG. 1 of the '678 patent) for joining trough membersand fittings. With best reference to FIGS. 6-7 of the '678 patent, aplurality of hardware is disclosed for joining the trough members. U.S.Pat. Nos. 5,316,243 and 5,752,781 show additional examples of couplings.

Several concerns arise with cable routing systems, including the ease ofinstallation of the troughs, couplings, and fittings. A further concernis removing components at a later date, such as to substitute differentfunctional elements into the system. Rigid systems provide adequatefiber support and protection. However, such prior art systems can besomewhat difficult to install, and modify later.

SUMMARY OF THE INVENTION

The present invention relates to a telescoping cable trough section fora cable routing system. The cable trough section includes first andsecond U-shaped trough sections extending in a longitudinal directionand each including a terminal end and a receiving end. The receivingends are slideably mated for sliding movement along the longitudinaldirection. The terminal ends can be joined to other system components,including couplings for joining to other trough sections or fittings inthe cable routing system.

Preferably, the terminal ends of the first and second trough sectionsinclude ends shaped to mate with the same coupling. Preferably, theterminal ends define the same coupling profile.

In one preferred embodiment, each of the first and second troughsections includes two upright walls. One of the first and second troughsections includes longitudinal slots formed in the upright walls. Theother of the first and second trough sections includes longitudinalflanges on the upright walls which are slideably received in thelongitudinal slots of the other trough section.

In one preferred embodiment, a retention system retains the first andsecond trough sections together so that the parts do not slide apartbefore installation in the system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a portion of a cable routing system,including a telescoping trough in accordance with the present invention,and a horizontal trough section, and a fitting as exemplary componentsused with the telescoping trough;

FIG. 2 is a top perspective view of the telescoping trough of FIG. 1;

FIG. 3 is a bottom perspective view of the telescoping trough;

FIG. 4 is a side view of the telescoping trough;

FIG. 5 is a top view of the telescoping trough;

FIG. 6 is a bottom view of the telescoping trough;

FIG. 7 is a top perspective view of the telescoping trough in aretracted state;

FIG. 8 is a side view of the telescoping trough of FIG. 7;

FIG. 9 is a cross-sectional end view of the telescoping trough, takenalong lines 9-9 of FIG. 8;

FIG. 10 is a top perspective view of the first trough section of thetelescoping trough;

FIG. 11 is a side view of the first trough section;

FIG. 12 is a cross-sectional end view of the telescoping trough, takenalong lines 12-12 of FIG. 11;

FIG. 13 is a top perspective view of the second trough section of thetelescoping trough;

FIG. 14 is a bottom perspective view of the second trough section;

FIG. 15 is a side view of the second trough section;

FIG. 16 is a cross-sectional end view of the second trough section,taken along lines 16-16 of FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, a cable routing system 10 is shown inaccordance with the principals of the present invention. Cable routingsystem 10 includes a telescoping trough 12 mounted to a coupling 14 onone terminal end 30. Coupling 14 joins telescoping trough 12 tohorizontal trough section 16. An opposite terminal end 32 of telescopingtrough 12 is mounted to a second coupling 14 which is mounted to afitting 18 (T-fitting). End 30 can be spaced from end 32 in atelescoping manner.

Couplings 14 are described in greater detail in U.S. Pat. No. 5,752,781,the disclosure of which is incorporated by reference. Terminal ends 30,32 are received in generally U-shaped channels in couplings 14.Resilient tabs 14 a engage holes 29 in terminal ends 30,32. Fasteners 14b of coupling 14 are screwed down to secure couplings 14 to trough 12.Cable retention members 14 c are added to help retain the cables in thevarious trough and fitting components. Additional couplings, troughs andfittings useful in system 10 with trough 12 are disclosed in U.S. Pat.Nos. 5,067,678; 5,316,243; 5,923,753 and 5,937,131, the disclosures ofwhich are also incorporated by reference.

Telescoping trough 12 has a variable or changeable length so as to beusable in a variety of circumstances in system 10 or other systems.Trough 12 is useful in system 10 where the distance between couplings 14is any distance between a maximum and minimum for the amount ofextension for telescoping trough 12. This allows for less precise designand assembly of system 10. Instead of telescoping trough 12, a singlepiece trough would have to be custom cut or manufactured to fit betweencouplings 14.

Because the length of telescoping trough 12 is variable, telescopingtrough 12 can drop into position between couplings 14, in a slightlyretracted state, and then be expanded to complete the cable pathwaybetween couplings 14. Once expanded, resilient tabs 14 a, and fasteners14 b secure trough 12 in place. Further, system 10 can be accessed formodification by releasing tabs 14 a, and fasteners 14 b, and thenretracting telescoping trough 12 to allow its removal.

Telescoping trough 12 includes a first trough section 24 and a secondtrough section 26 which are slideably mated with one another. Firsttrough section 24 and second trough section 26 include a variableoverlap portion 28 (compare FIGS. 5 and 8). Terminal ends 30, 32 oftelescoping trough 12 each join to one of couplings 14. Terminal ends30, 32 each have a profile which permits either end 30, 32 to be matedwith either coupling 14. Such a shaping for the ends allows ease ofassembly since trough 12 can be inserted in either orientation for ends30, 32. Preferably, the end profiles of trough 12 are identical.Terminal ends 30, 32 also mate with other couplings or fittings asdesired.

Telescoping trough 12 defines a generally U-shaped channel with uprightwalls 34 extending from a base wall 36. Interior 35 defines the cablepathway for the optical fiber (or copper) cables.

First trough section 24 includes a receiving end 40, and an oppositeterminal end 42. First trough section 24 defines a generally U-shapedchannel including upright wall sections 44 extending from a base wallsection 46. First trough section 24 includes an outside surface 48 andan inside surface 50. Outside surface 48 can include a variety of shapesincluding strengthening ribs 49 and structure 51 for mounting to systemsupport hardware which holds system 10 in place, such as in a ceilingmount.

First trough section 24 includes upper flanges 52 at an upper portion ofupright wall sections 44 each defining a slot 54 for mating withportions of second trough section 26, as will be described below infurther detail. Base wall section 46 further includes a projecting tab56 facing upwardly. Tab 56 includes a ramp surface 58, and a shoulder60. Tab 56 is used to retain first and second trough sections 24, 26together, as will be described below in further detail.

Second trough section 26 includes a receiving end 70, and an oppositeterminal end 72. Upright wall sections 74 extend from base wall section76. Second trough section 26 includes an outside surface 78 and aninside surface 80. At an upper portion of upright wall sections 74,upper flanges 82 extend outwardly for receipt in slots 54 of firsttrough section 24. In the mated state, inside surface 50 of first troughsection 24 closely receives outside surface 78 of second trough section26. Inside surface 80 and the exposed inside surface 50 not covered bysecond trough section 26, form a closed U-shaped trough for receipt ofthe cables passing through trough 12.

Flanges 82 each include small upper ridges 84 extending perpendicularlyto flanges 82 to assist with a secure fit of flanges 82 in slots 54.Ridges 84 help fill the height of slots 54, yet do not promote bindingof the parts during sliding movement (see FIG. 9).

Base wall section 76 of second trough section 26 includes an elongatedslot 86 for receipt of tab 56 of first trough section 24 (see FIG. 9).The interaction of tab 56 and slot 86 keeps second trough section 26from being separated from first trough section 24 and further definesthe maximum length of trough 12. Ramp surface 58 allows for the twotrough sections 24, 26 to be mounted together during assembly byaligning the two parts (receiving end 70 inside receiving end 40, andflanges 82 aligned with slots 54) and pressing them together in theaxial direction. Once tab 56 is positioned in slot 86, shoulder 60prevents the two pieces from being separated. Preferably first andsecond trough sections 24, 26 are made from molded plastic. Tab 56 canbe separated from slot 86 by manually pressing base wall section 46 awayfrom base wall section 76.

Base wall section 76 of second trough section 26 preferably includes amiddle thickened area 90, which allows for convenient molding fromplastic. Middle thickened area 90 provides an increased thickness inportions of second trough section 26 adjacent to slot 86. Thickened area90 promotes material flow during molding. Receiving end 70 of secondtrough section 26 preferably includes a tapered receiving end 94, tohelp protect fiber optic cables contained within telescoping trough 12from contacting any sharp edges. End 94 tapers to a minimum wallthickness at end 70. Second trough section 26 further includes anenlarged terminal end 98 relative to a reduced central section 99 andreceiving end 70 which allows for terminal end 72 to have a similarcoupling profile as terminal end 42 of first trough section 24. Enlargedterminal end 98 also provides a stop for limiting the minimum length oftrough 12.

The above specification, examples and data provide a completedescription of the manufacture and use of the invention. Since manyembodiments of the invention can be made without departing from thespirit and scope of the invention, the invention resides in the claimshereinafter appended.

1. A method of assembling a cable routing system comprising the stepsof: providing first and second U-shaped spaced apart end members;providing a telescoping U-shaped trough with first and second troughsections, the first and second trough sections each having a terminalend and a receiving end, the receiving ends of the first and secondtrough sections being in sliding contact with one another, the terminalends of the first and second trough sections having the same connectingconfiguration such that the telescoping U-shaped trough is reversible;positioning the reversible telescoping U-shaped trough between the firstand second end members; and connecting the terminal ends of the firstand second trough sections of the reversible telescoping U-shaped troughto the first and second end members, wherein the receiving ends of thefirst and second trough sections remain freely slideable relative to oneanother during use of the completely assembled cable routing system sothat the first and second trough sections slide relative to one anotherwhen only one terminal end of one of the first and second troughsections is disconnected from the respective first and second endmember.
 2. The method of claim 1, wherein the step of providing thetelescoping U-shaped trough includes providing the first and secondtrough sections in sliding contact, sliding movement of the first andsecond trough sections being limited between a maximum extensionposition and a minimum extension position to prevent separation of thefirst and second trough sections.
 3. A method of assembling a cablerouting system comprising the steps of: providing first and second endmembers, the end members being spaced apart a fixed distance; providinga telescoping cable trough with first and second trough sections havingjoined ends, the joined ends of the first and second trough sectionsbeing in sliding contact with one another; positioning the telescopingcable trough between the first and second end members; and selectivelyconnecting the first trough section to either one of the first andsecond end members, the first trough section being connectable to bothof either one of the first and second end members; and connecting thesecond trough section to the other of the first and second end members;wherein the joined ends of the first and second trough sections remainfreely slideable relative to one another during use of the completelyassembled cable routing system so that the first and second troughsections slide relative to one another when only one connected end ofone of the first and second trough sections is disconnected from therespective first and second end member.
 4. The method of claim 3,wherein the step of selectively connecting the first and second troughsections to the first and second ends members includes connecting thefirst trough section to the first end member.
 5. The method of claim 3,wherein the step of selectively connecting the first and second troughsections to the first and second ends members includes connecting thefirst trough section to the second end member.
 6. The method of claim 3,wherein the step of providing a telescoping cable trough includesproviding a telescoping cable trough with first and second slideabletrough sections having substantially the same coupling profile forselectively coupling one of the first and second trough sections toeither of the first and second end members.
 7. The method of claim 3,further including sliding the trough sections relative to one another tofit between the first and second end members.
 8. The method of claim 7,further including engaging flanges of the second trough section withslots formed in the first trough section and sliding the trough sectionsrelative to one another.
 9. The method of claim 7, further includingsliding the trough sections relative to one another until a slot and tabconnection of the telescoping cable trough stops further slidingmovement.
 10. The method of claim 3, further including varying anoverall length of the telescoping cable trough during assembly by: a)retracting the telescoping cable trough to position the cable troughbetween the first and second end members; and b) expanding thetelescoping cable trough to connect the first and second sections to thefirst and second end members.
 11. The method of claim 3, wherein thestep of providing the telescoping cable trough includes providing thefirst and second trough sections in sliding contact, sliding movement ofthe first and second trough sections being limited between a maximumextension position and a minimum extension position to preventseparation of the first and second trough sections.
 12. A method ofassembling a cable routing system comprising the steps of: providingfirst and second cable trough members, each of the cable trough membershaving ends; providing a telescoping trough with first and second troughsections, the first and second trough sections being in sliding contactwith one another, sliding movement of the first and second troughsections being limited between a minimum extension position and amaximum extension position by a tab and slot connection, the tab andslot connection preventing sliding separation of the first and secondtrough sections while permitting sliding contact of the first and secondtrough sections between the minimum extension position and the maximumextension position; positioning the telescoping trough between the endsof the first and second cable trough members; and connecting the firstand second trough sections to the ends of the first and second cabletrough members, wherein the first and second trough sections remainfreely slideable upon disconnecting at least one of the first and secondtrough sections from the respective end of the first and second troughmembers.
 13. The method of claim 12, wherein the step of providing thetelescoping trough includes providing a U-shaped telescoping trough. 14.The method of claim 12, wherein the step of providing the telescopingtrough includes providing a telescoping trough with first and secondtrough sections having substantially the same coupling profile forselectively coupling one of the first and second trough sections toeither of the ends of the first and second cable trough members.
 15. Themethod of claim 12, further including sliding the trough sectionsrelative to one another to fit between the ends of the first and secondcable trough members.
 16. The method of claim 15, further includingengaging flanges of the second trough section with slots formed in thefirst trough section and sliding the trough sections relative to oneanother.
 17. The method of claim 15, further including sliding thetrough sections relative to one another until the slot and tabconnection of the telescoping trough stops further sliding movementbeyond the maximum extension position.
 18. The method of claim 15,further including sliding the trough sections relative to one anotheruntil the tab and slot connection of the telescoping trough stopsfurther sliding movement beyond the minimum extension position.
 19. Themethod of claim 12, further including varying an overall length of thetelescoping trough during assembly by: a) retracting the telescopingtrough to position the telescoping trough between the ends of the firstand second cable trough members; and b) expanding the telescoping troughto connect the first and second trough sections to the ends of the firstand second cable trough members.